The memo said biological differences explained why women are not represented in tech equally to men

Google CEO Sundar Pichai said on Monday in an email to employees that the memo crossed the line of the company's code of conduct 'by advancing harmful gender stereotypes in our workplace.' (Marcio Jose Sanchez/The Associated Press)

A 28-year-old former Google engineer who was fired over a memo he wrote about gender differences said Tuesday he's exploring all his legal options and has already filed a labour complaint in the U.S. over his treatment.

James Damore, whose weekend memo caused an uproar online, said in an email he was terminated late Monday for "perpetuating gender stereotypes." He said that prior to being fired, he had filed a complaint with the National Labor Relations Board and that "it's illegal to retaliate against a NLRB charge."

A filing by Damore with the board Monday alleged he was subjected to "coercive statements" while working at Google's Mountain View, Calif., campus.

A Google spokesperson said Tuesday that the company could not have retaliated because it was unaware of his labour complaint until reading about it in the media after his dismissal. As of Tuesday afternoon, the company said it had not been sent notice of the complaint by the board.

The board declined to comment.

Memo called 'offensive and not OK'

Google CEO Sundar Pichai on Monday said in an email to employees that, while he supports free expression by company workers, Damore's memo crossed the line of the company's code of conduct "by advancing harmful gender stereotypes in our workplace." Pichai added that he was cutting short a family vacation overseas to address staff in a town hall Thursday.

"To suggest a group of our colleagues have traits that make them less biologically suited to that work is offensive and not OK," Pichai wrote.

Google's just-hired head of diversity, Danielle Brown, responded earlier with her own memo, saying Google is "unequivocal in our belief that diversity and inclusion are critical to our success." She said change is hard and "often uncomfortable."

Damore's memo, originally circulated on an internal Google discussion group, begins by saying only honest discussion will address a lack of equity. But it also asserts that women "prefer jobs in social and artistic areas" while more men "may like coding because it requires systemizing."

The memo says biological differences between men and women may explain why women are not equally represented in the technology industry.

Legal protection remains unclear

Damore's filing with the NLRB cites a part of the labour relations act that gives employees the right to engage in "protected concerted" activities. That includes being active on social media, though it's unclear if his memo, written on a Google Doc and submitted to an employee-only forum, qualifies for such protection. The first tweets about the post by other Google employees began Friday, though a company spokesperson said the document appeared to have been created weeks earlier.

The Twitter hashtag #JamesDamore was drawing a storm of opinions both attacking Damore for his memo and his qualifications as an engineer, and criticizing Google for his dismissal.

The battling messages come as Silicon Valley grapples with accusations of sexism and discrimination. Google is also in the midst of a Department of Labor investigation into whether it pays women less than men, while Uber's CEO recently lost his job amid accusations of widespread sexual harassment and discrimination.

Leading tech companies, including Google, Facebook and Uber, have said they are trying to improve hiring and working conditions for women. But diversity numbers are barely changing.